Enhanced photo-, sono- and sonophotocatalysis of methylene blue via SnO₂ nanoparticle supported on nanographene platelets (NGP)

In our previous study, we have reported the catalytic (photo- and sono-) performance of SnO₂ nanoparticles in methylene blue (MB) removal from aqueous solution. In this study, SnO₂/nanographene platelets (NGP) composites were fabricated by depositing SnO₂ nanoparticle onto nanographene platelets surface to develop photo-, sono-, and sonophotocatalysts, SnO₂ nanoparticle, and SnO₂/NGP composites were successfully synthesized using the sol-gel and coprecipitation method, respectively. The nanographene platelets (NGP) content was varied from 5, 10, and 15 weight percentages (wt.%). The optical properties and thermal stability of the samples were characterized using X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Thermal Gravimetric Analysis (TGA). The catalytic ability of the samples was investigated using photo-, sono-, and sonophoto degradation of MB which was observed when nanographene platelets (NGP) were added into SnO₂ nanocomposite. The photo-, sono- and sonophotocatalytic activities of SnO₂/NGP composites on dyes were analyzed by measuring the change in absorbance of dyes under UV-spectrophotometer. The degradation of the organic dyes has been calculated by monitoring the degradation in concentration of the dyes before and after irradiation of UV light, ultrasound, and both of them respectively. The influence of other parameters such as catalyst dosage, pH, and scavenger have also been investigated. The results showed that SnO₂/NGP composite with 10 weight percent (wt.%) has better catalytic performance than pure SnO₂ nanoparticle. The reusability tests have also been done to ensure the stability of the used catalysts.